To use it in Visual Studio, put the snippet in a .snippet file and save it in your snippets directory, then go to Tools => Code Snippets Manager => Add. Once it's added, you can use the standard CTRK K+X to access it.

The only thing this gives you over the built-in snippet for region is the flexibility to add the trailing comment to indicate the region's end. You can also further customise this by adding additional expansions.

NOTE: the sentinal $end$ marks where you want the cursor to land when the operation is complete.